# US 8,783,831 B2 · Fluid ejection device having firing chamber with contoured floor

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- Number: US 8,783,831 B2
- Document ID: US8783831B2
- Status: Granted
- Kind: B2
- Application number: 13/977,104
- Filed: 2012-01-30
- Published: 2013-10-31
- Granted: 2014-07-22
- Earliest claimed: 2011-01-31
- Assignees: Hewlett-Packard Development Company, L.P.
- Applicants: Peter Mardilovich; Lawrence H. White; Erik D. Torniainen
- Inventors: Peter Mardilovich; Lawrence H. White; Erik D. Torniainen
- Web page: https://patentgrep.com/patent/US8783831B2

## CPC

- B41J 2/14032: {Structure of the pressure chamber}
- B41J 2/14: Structure thereof {only for on-demand ink jet heads}
- B41J 2/14088: {Structure of heating means}
- B41J 2/1412: {Shape}
- B41J 2/14129: {Layer structure}
- B41J 2202/11: characterised by specific geometrical characteristics
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS

## Abstract

A fluid ejection device includes a firing chamber having a chamber floor with an orifice opposite the chamber floor and a heating element partially covering the chamber floor, a region of the chamber floor being contoured to define a cavity extending into the chamber floor.

## Claims

### Claim 1

A fluid ejection device comprising:
a firing chamber having a chamber floor and an orifice opposite the chamber floor; and
a heating element partially covering the chamber floor to define an uncovered region of the chamber floor;
wherein the uncovered region of the chamber floor is contoured to define a cavity extending into the chamber floor.

### Claim 2 (depends on 1)

The fluid ejection device of claim 1, wherein the heating element is a ring-type heating element having an inner perimeter that defines the uncovered region of the chamber floor.

### Claim 3 (depends on 2)

The fluid ejection device of claim 2, wherein the cavity perimeter is coextensive with the inner perimeter of the ring-type heating element.

### Claim 4 (depends on 2)

The fluid ejection device of claim 2, wherein the cavity has a perimeter that is smaller than the inner perimeter of the ring-type heating element.

### Claim 5 (depends on 2)

The fluid ejection device of claim 2, wherein the cavity is centered on the orifice.

### Claim 6 (depends on 1)

The fluid ejection device of claim 1, wherein the cavity includes a cavity floor and a mesa projecting from the cavity floor, thereby defining a well surrounding the mesa.

### Claim 7 (depends on 6)

The fluid ejection device of claim 6, wherein the cavity and mesa are centered on the orifice.

### Claim 8 (depends on 1)

The fluid ejection device of claim 1, wherein the cavity is a compound cavity, defining a sub-cavity formed in the cavity.

### Claim 9 (depends on 1)

The fluid ejection device of claim 1, wherein the cavity is an elongate cavity defining a major axis extending across the chamber floor.

### Claim 10 (depends on 9)

The fluid ejection device of claim 9, wherein the heating element includes a plurality of spaced heating element segments defining a central region on the chamber floor, and wherein the elongate cavity is in the central region.

### Claim 11 (depends on 1)

The fluid ejection device of claim 1, wherein the uncovered region of the chamber floor is contoured to define plural cavities in the chamber floor.

### Claim 12

A fluid ejection device comprising:
a firing chamber having a fluid inlet, an ejection orifice and a chamber floor opposite the ejection orifice, the chamber floor having a central region with a cavity formed therein; and
a heating element within the firing chamber, the heating element extending around the cavity.

### Claim 13 (depends on 12)

The fluid ejection device of claim 12, wherein the cavity is cylindrical.

### Claim 14 (depends on 12)

The fluid ejection device of claim 12, wherein the heating element is a ring-type resistor on the chamber floor.

### Claim 15

A fluid ejection device comprising:
a firing chamber having a chamber floor, one or more walls and a nozzle layer with an orifice opposite the chamber floor;
a ring-type heating element on the chamber floor, the heating element defining an inner perimeter; and
a cavity defined in the chamber floor, the cavity being coextensive with the inner perimeter.